Fuel sender and gas gauge in ‘63 and ‘64 Darts.

Is it an aftermarket sending unit? If so, it’s probably a little short arm piece of junk. Get the A100 sending unit that vans auto is making at least that has the long arm which helps a lot, but it still doesn’t have the progressively wound resistance. You’ll probably have to bend the arm a little bit to make it empty when it’s truly empty, but it works way better than those little short arms that are being sold as replacements.